Performing context-rich attribute-based encryption on a host

ABSTRACT

Some embodiments provide a context engine that supplies contextual-attributes to several context-based service engines on its host computer. Different embodiments use different types of context-based service engines. For instance, in some embodiments, the attribute-based service engines include an encryption engine that performs context-based encryption or decryption operations to encrypt data messages from the machines, or to decrypt data messages received for the machines.

RELATED APPLICATIONS

Benefit is claimed under 35 U.S.C. 119(a)-(d) to Foreign Application Serial No. 201741040827 filed in India entitled “PERFORMING CONTEXT-RICH ATTRIBUTE-BASED ENCRYPTION ON A HOST”, on Nov. 15, 2017, by NICIRA, INC., which is herein incorporated in its entirety by reference for all purposes.

BACKGROUND

Middlebox services have historically been hardware appliances that are implemented at one or more points in a network topology in an enterprise or a datacenter. With the advent of software defined networking (SDN) and network virtualization, traditional hardware appliances do not take advantage of the flexibility and control that is provided by SDN and network virtualization. Accordingly, in recent years, some have suggested various ways to provide middlebox services on hosts. Most of these middlebox solutions, however, do not take advantage of the rich-contextual data that can be captured for each data message flow on the host. One reason for this is that existing techniques do not provide an efficient, distributed scheme for filtering the thousands of captured-contextual attributes in order to efficiently process service rules that are defined in terms of much smaller sets of contextual attributes.

BRIEF SUMMARY

Some embodiments of the invention provide a novel architecture for capturing contextual attributes on host computers that execute one or more machines, and for consuming the captured contextual attributes to perform services on the host computers. The machines are virtual machines (VMs) in some embodiments, containers in other embodiments, or a mix of VMs and containers in still other embodiments.

Some embodiments execute a guest-introspection (GI) agent on each machine from which contextual attributes need to be captured. In addition to executing one or more machines on each host computer, these embodiments also execute a context engine and one or more attribute-based service engines on each host computer. Through the GI agents of the machines on a host, the context engine of that host in some embodiments collects contextual attributes associated with network events and/or process events on the machines. As further described below, the context engine then provides the contextual attributes to the service engines, which, in turn, use these contextual attributes to identify service rules that specify context-based services to perform on processes executing on the machines and/or data message flows sent by or received for the machines.

In some embodiments, the context engine of a host collects contextual attributes from the GI agents of the machines on that host through a variety of different ways. For instance, in some embodiments, the GI agent on a machine registers hooks (e.g., callbacks) with one or more modules (e.g., kernel-space modules or user-space modules) in the machine's operating system for all new network connection events and all new process events.

Upon occurrence of a new network connection event, the GI agent receives a callback from the OS and based on this callback, provides a network event identifier to the context engine. The network event identifier provides a set of attributes pertaining to the network event. These network event attributes in some embodiments include a five-tuple identifier (i.e., source port and IP address, destination port and IP address, and protocol) of the requested network connection, process identifier of the process requesting the network connection, a user identifier associated with the requesting process, and a group identifier (e.g., an activity directory (AD) identifier) associated with the requesting process.

In some embodiments, the context engine directs the GI agent to collect from the OS modules additional process parameters that are associated with the process identifier (ID) that it received with the network event. These additional process parameters in some embodiments include the process name, the process hash, the process path with command line parameters, the process network connection, the process-loaded modules, and one or more process consumption parameters specifying the process' consumption of one or more resources of the machine (e.g., central processing unit consumption, network consumption, and memory consumption). Instead of using the process identifier to query the GI agent for additional process parameters associated with a network event, the context engine in other embodiments receives all the process parameters associated with a network event in one shot when the GI agent reports the network event to the context engine.

The OS in some embodiments holds up a new network event (i.e., does not start sending data messages for the network event) until the GI agent directs it to proceed with processing the network event. In some of these embodiments, the GI agent only allows the OS to proceed with processing the network event after the context engine has collected all the needed attributes for this event (e.g., after receiving a message from the context engine that specifies that it has received all the process or network attributes that it needs for the new network event).

In some embodiments, the context engine uses the process hash that it receives from the GI agent to identify the name and version of the application (i.e., the software product) to which the process belongs. To do this, the context engine in some embodiments stores process hashes and associated application names/versions, compares the process hash that it receives from the GI agent with the stored process hashes to identify a matching hash, and then uses the application name/version of the matching hash as the application name and version of the process associated with the event.

In some embodiments, the context engine obtains the process hashes and application names/versions from one or more network or compute managers, which may operate on another device or computer. In other embodiments, the context engine provides the hash associated with a process identifier to a network or compute manager, which then matches this hash to its process hash records and provides the application name/version of the associated process to the context engine. Once the context engine obtains the application name/version associated with a network event, it can provide the name and version attributes to the attribute-based service engines, which can use this information (i.e., the application name and/or version) to identify the service rule to enforce.

Upon occurrence of a process event, the GI agent receives a callback from the OS and based on this callback, provides a process event identifier to the context engine. The process event identifier provides a set of attributes pertaining to the process event. This set of attributes includes the process identifier in some embodiments. In some embodiments, this set also includes a user identifier and a group identifier (e.g., an activity directory (AD) identifier).

In some embodiments, the GI agent provides all the process parameters (e.g., process identifier, user ID, group ID, process name, process hash, loaded module identifiers, consumption parameters, etc.) associated with a process event to the context engine when it reports the process event to the context engine. In other embodiments, the context engine directs the GI agent to collect from the OS modules additional process parameters that are associated with the process identifier that context engine received with the process event. These additional process parameters in some embodiments are the same (e.g., process name, process hash, loaded module identifiers, consumption parameters, etc.) as the process parameters mentioned above for reported network events.

The context engine of some embodiments augments the contextual attributes that it receives from the GI agent with contextual attributes that it receives from other modules that execute on the host. For instance, in some embodiments, a deep packet inspection (DPI) module executes on the host. The context engine or another module (e.g., a firewall engine) directs this DPI engine to examine data messages of a data message flow associated with a process ID to identify the type of traffic being sent in these data messages by the application associated with the process ID.

The identified traffic-type identity is today commonly referred to as the AppID. Also, currently there are a number of DPI modules that analyze messages of a data message flow to generate the AppID. In some embodiments, the context engine combines the AppID that it obtains for a network event with other context attributes that it identifies for this event (e.g., by using the event's five-tuple identifier to associate the AppID with the collected contextual attributes), in order to produce a very rich set of attributes that the service engines can then use to perform their services. This rich set of attributes provides true application identity (i.e., the application name, application version, application traffic type, etc.), based on which the service engines can perform their services.

Also, in some embodiments, a threat detection module executes on the host computer along with the context engine. Once the context engine obtains a set of process parameters that specify that a process has started on a machine or is sending data messages on the machine, the context engine in some embodiments provides one or more process parameters (e.g., process hash, application name, application version, AppID, other process parameters, etc.) to the threat detection module. This threat detection module then generates a threat level indicator (e.g., low, medium, high, etc.) for the identified process and provides this threat level indicator to the context engine. The context engine then provides this threat level indicator to one or more service engines as another contextual attribute for performing services on a new process event or the data messages of a new network event; a service engine can use the threat level indicator as another attribute to identify service rules to enforce.

The context engine employs a push model in some embodiments to distribute the collected contextual attributes to the service engines, employs a pull model in other embodiments to distribute these attribute to the service engines, while in other embodiments, employing a push model for some service engines and a pull model for other service engines. In the push model, the context engine distributes to a service engine the contextual attributes that it collects for a process event or a network event with the process's identifier and/or the network event's flow identifier (e.g., the flow's five-tuple identifier). In some embodiments, the context engine distributes to the service engine only the contextual attributes that are relevant for that service engine's service rules.

In the pull model, the context engine receives queries from a service engine for the contextual attributes that the context engine has collected for a particular process or network connection. In some embodiments, the context engine receives a process ID or a flow identifier (e.g., five-tuple identifier) with a query from the service engine, and uses the received identifier to identify the attribute set that it has to provide to the service engine. In some embodiments, the context engine generates a service token (also called a service tag) for the collection of attributes that are relevant for the service engine, and provides this service token to another module (e.g., the GI agent or another module on the host) to pass along to the service engine (e.g., pass along in a data message's encapsulating tunnel header). The service engine then extracts the service token and provides this service token to the context engine in order to identify the contextual attributes that the context engine has to provide to the service engine.

The context engine in some embodiments provides contextual-attributes to several context-based service engines on its host computer. In some embodiments, the context engine and the service engines are all kernel space components of a hypervisor on which multiple VMs or containers execute. In other embodiments, the context engine and/or one or more service engines are user space processes. For example, one or more service engines in some embodiments are service VMs (SVMs).

Different embodiments use different types of context-based service engines. For instance, in some embodiments, these attribute-based service engines include (1) a firewall engine that performs context-based firewall operations on data messages sent by or received for the machines, (2) a process control engine that enforces context-based process control operations (e.g., process assessment and termination operations) on processes started on the machines, (3) a load balancing engine that performs context-based load balancing operations to distribute the data message flows from the machines to different destination or service nodes in one or more destination/service node clusters, and (4) an encryption engine that performs context-based encryption or decryption operations to encrypt data message from the machines, or to decrypt data messages received for the machines.

Another context-based service engine in some embodiments is a discovery service engine. In some embodiments, the discovery engine captures new process events and new network events from the context engine, along with the contextual attributes that the context engine collects for these process and network events. The discovery service engine then relays these events and their associated contextual attributes to one or more network managers (e.g., servers) that provide a management layer that allows network administrators to visualize events in a datacenter and specify policies for compute and network resources in the datacenter.

In relaying these events and attributes to the network management layer, the discovery module of some embodiments performs some pre-processing of these events and attributes. For example, in some embodiments, the discovery module filters some of the network or process events, while aggregating some or all of these events and their attributes. Also, in some embodiments, the discovery engine directs the context engine to collect additional contextual attributes for process or network events through the GI agents or other modules (e.g., the DPI engine or threat detection engine), or to capture other types of events, such as file events and system events.

For example, in some embodiments, the discovery engine directs the context engine to build an inventory of the applications installed on the machines, and to periodically refresh this inventory. The discovery engine might so direct the context engine at the request of the management plane, or based on operational configurations that the management or control plane specifies for the discovery engine. In response to the request from the discovery engine, the context engine in some embodiments has each GI agent on each of its host's machine discover all installed processes on the machine, and all running processes and services.

After building an inventory of installed applications and the running processes/services, the discovery engine of a host computer in a datacenter provides this information to the network/compute managers in the management plane. In some embodiments, the management plane collects contextual attributes from sources other than the host computer discovery and context engines. For instance, in some embodiments, the management plane collects from one or more servers compute context (e.g., cloud context from cloud vendors, or compute virtualization context by datacenter virtualization software), identity context from directory service servers, mobility context from mobility management servers, endpoint context from DNS (domain name server) and application inventory servers, network context (e.g., virtual network context from network virtualization server), etc.

By collecting the contextual information (e.g., information from the discovery and context engines and/or information from other context sources), the management plane can provide a user interface to the network/compute administrators to visualize the compute and network resources in the datacenter. Moreover, the collected contextual attributes allow the management plane to provide controls through this user interface for these administrators to specify context-based service rules and/or policies. These service rules/policies are then distributed to the host computers so that service engines on these computers can perform context-based service operations.

The preceding Summary is intended to serve as a brief introduction to some embodiments of the invention. It is not meant to be an introduction or overview of all inventive subject matter disclosed in this document. The Detailed Description that follows and the Drawings that are referred to in the Detailed Description will further describe the embodiments described in the Summary as well as other embodiments. Accordingly, to understand all the embodiments described by this document, a full review of the Summary, Detailed Description, the Drawings and the Claims is needed. Moreover, the claimed subject matters are not to be limited by the illustrative details in the Summary, Detailed Description and the Drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth in the appended claims. However, for purposes of explanation, several embodiments of the invention are set forth in the following figures.

FIG. 1 illustrates a host computer that uses the context engine and context-based service engines of some embodiments of the invention.

FIG. 2 illustrates a more-detailed example of a host computer that in some embodiments is used to establish a distributed architecture for configuring and performing context-rich, attribute-based services in a datacenter.

FIG. 3 illustrates a process performed by a context engine of some embodiments.

FIG. 4 illustrates a process that the context engine performs to collect the user and group identifiers each time it receives a new network connection event from a GI agent.

FIG. 5 illustrates an example of such context-based encryption rules.

FIG. 6 illustrates a process that the encryptor of some embodiments performs to encrypt a data message sent by a VM on a host.

FIG. 7 illustrates a process that an encryption engine performs to decrypt an encrypted data message that a forwarding-element port receives on a destination host that executes a destination VM of the data message.

FIG. 8 illustrates a process that the encryption engine performs to decrypt an encrypted data message that includes the key identifier in its header.

FIG. 9 illustrates an example of how the service engines are managed in some embodiments.

FIG. 10 conceptually illustrates a computer system with which some embodiments of the invention are implemented.

DETAILED DESCRIPTION

In the following detailed description of the invention, numerous details, examples, and embodiments of the invention are set forth and described. However, it will be clear and apparent to one skilled in the art that the invention is not limited to the embodiments set forth and that the invention may be practiced without some of the specific details and examples discussed.

Some embodiments of the invention provide a novel architecture for capturing contextual attributes on host computers that execute one or more machines, and for consuming the captured contextual attributes to perform services on the host computers. Some embodiments execute a guest-introspection (GI) agent on each machine from which contextual attributes need to be captured. In addition to executing one or more machines on each host computer, these embodiments also execute a context engine and one or more attribute-based service engines on each host computer. Through the GI agents of the machines on a host, the context engine of that host in some embodiments collects contextual attributes associated with network events and/or process events on the machines. The context engine then provides the contextual attributes to the service engines, which, in turn, use these contextual attributes to identify service rules that specify context-based services to perform on processes executing on the machines and/or data message flows sent by or received for the machines.

As used in this document, data messages refer to a collection of bits in a particular format sent across a network. One of ordinary skill in the art will recognize that the term data message may be used herein to refer to various formatted collections of bits that may be sent across a network, such as Ethernet frames, IP packets, TCP segments, UDP datagrams, etc. Also, as used in this document, references to L2, L3, L4, and L7 layers (or layer 2, layer 3, layer 4, layer 7) are references respectively to the second data link layer, the third network layer, the fourth transport layer, and the seventh application layer of the OSI (Open System Interconnection) layer model.

FIG. 1 illustrates a host computer that uses the context engine and context-based service engines of some embodiments of the invention. As shown, host computer 100 includes several data compute nodes 105, a context engine 110, several context-based service engines 130, a threat detector 132, and a deep packet inspection (DPI) module 135. The context-based service engines include a discovery engine 120, a process control engine 122, an encryption engine 124, a load balancer 126 and a firewall engine 128. It also includes context-based service rule storages 140, and an attribute storage 145.

The DCNs are endpoint machines executing on the host computer 100. The DCNs are virtual machines (VMs) in some embodiments, containers in other embodiments, or a mix of VMs and containers in still other embodiments. On each DCN, a GI agent 150 executes in order to collect contextual attributes for the context engine 110. In some embodiments, the context engine 110 collects contextual attributes from the GI agents 150 of the DCNs on its host through a variety of different ways. For instance, in some embodiments, the GI agent on a DCN registers hooks (e.g., callbacks) with one or more modules (e.g., kernel-space modules or user-space modules) in the DCN's operating system for all new network connection events and all new process events.

Upon occurrence of a new network connection event, the GI agent 150 receives a callback from its DCN's OS and based on this callback, provides a network event identifier to the context engine 110. The network event identifier provides a set of attributes pertaining to the network event. These network event attributes in some embodiments include a five-tuple identifier (i.e., source port and IP address, destination port and IP address, and protocol) of the requested network connection, process identifier of the process requesting the network connection, a user identifier associated with the requesting process, and a group identifier (e.g., an activity directory (AD) identifier) associated with the requesting process.

In some embodiments, the context engine directs the GI agent 150 to collect from the OS modules additional process parameters that are associated with the process identifier (ID) that it received with the network event. These additional process parameters in some embodiments include the process name, the process hash, the process path with command line parameters, the process network connection, the process-loaded modules, and one or more process consumption parameters specifying the process' consumption of one or more resources of the machine (e.g., central processing unit consumption, network consumption, and memory consumption). Instead of using the process identifier to query the GI agent 150 for additional process parameters associated with a network event, the context engine 110 in other embodiments receives all the process parameters associated with a network event in one shot when the GI agent reports the network event to the context engine.

The OS of the DCN in some embodiments holds up a new network event (i.e., does not start sending data messages for the network event) until the GI agent 150 directs it to proceed with processing the network event. In some of these embodiments, the GI agent 150 only allows the OS to proceed with processing the network event after the context engine 110 has collected all the needed attributes for this event (e.g., after receiving a message from the context engine that specifies that it has received all the process or network attributes that it needs for the new network event).

In some embodiments, the context engine 110 uses the process hash that it receives from the GI agent 150 to identify the name and version of the application (i.e., the software product) to which the process belongs. To do this, the context engine 110 in some embodiments stores process hashes and associated application names/versions, compares the process hash that it receives from the GI agent with the stored process hashes to identify a matching hash, and then uses the application name/version of the matching hash as the application name and version of the process associated with the event.

In some embodiments, the context engine 110 obtains the process hashes and application names/versions from one or more network or compute managers, which may operate on another device or computer. In other embodiments, the context engine provides the hash associated with a process identifier to a network or compute manager, which then matches this hash to its process hash records and provides the application name/version of the associated process to the context engine. Once the context engine obtains the application name/version associated with a network event, it can provide the name and version attributes to the attribute-based service engines, which can use this information (i.e., the application name and/or version) to identify the service rule to enforce.

Upon occurrence of a process event on a DCN 105, the DCN's GI agent 150 in some embodiments receives a callback from the DCN's OS and based on this callback, provides a process event identifier to the context engine 110. The process event identifier provides a set of attributes pertaining to the process event. This set of attributes includes the process identifier in some embodiments. In some embodiments, this set also includes a user identifier and a group identifier (e.g., an activity directory (AD) identifier).

In some embodiments, the GI agent provides all the process parameters (e.g., process identifier, user ID, group ID, process name, process hash, loaded module identifiers, consumption parameters, etc.) associated with a process event to the context engine when it reports the process event to the context engine. In other embodiments, the context engine directs the GI agent to collect from the OS modules additional process parameters that are associated with the process identifier that context engine received with the process event. These additional process parameters in some embodiments are the same (e.g., process name, process hash, loaded module identifiers, consumption parameters, etc.) as the process parameters mentioned above for reported network events.

The context engine 110 of some embodiments augments the contextual attributes that it receives from the GI agents 150 with contextual attributes that it receives from other modules that execute on the host. The DPI module 135 (also referred to as the deep packet inspector) and the threat detector 132 (also referred to as the threat inspection module) are two such modules that provide context attributes to augment those that the context engine collects from the GI agents 150. In some embodiments, a DPI module is directed by the context engine 110 or another module (e.g., a firewall engine 128) to examine data messages of a data message flow associated with a process ID to identify the type of traffic being sent in these data messages by the application associated with the process ID.

The identified traffic-type identity is today commonly referred to as the AppID. Also, currently there are a number of DPI modules that analyze messages of a data message flow to generate the AppID for the data message flow. In some embodiments, the context engine combines the AppID that it obtains for a network event with other context attributes that it identifies for this event, in order to produce a very rich set of attributes that the service engines can then use to perform their services. This rich set of attributes provides true application identity (i.e., the application name, application version, application traffic type, etc.), based on which the service engines can perform their services. In some embodiments, the context engine 110 uses a network event's five-tuple identifier to associate the AppID for this events data message flow with the contextual attributes that the context engine collects from the GI agent of the DCN associated with the data message flow (e.g., of the DCN from which the data message flow emanates).

The threat detector 132 provides a threat level indicator that specifies the threat level associated with a particular application that is executing on a DCN. Once the context engine obtains a set of process parameters that specify that a process has started on a machine or is sending data messages on the machine, the context engine in some embodiments provides one or more process parameters (e.g., process hash, application name, application version, AppID, other process parameters, etc.) to the threat detection module.

This threat detection module then generates a threat level indicator (e.g., low, medium, high, etc.) for the identified process and provides this threat level indicator to the context engine. In some embodiments, the threat detector assigns a threat score to an application running on a DCN based on various application behavioral factors, such as (1) whether it does poor input validation, (2) whether it passes authentication credentials over unencrypted network links, (3) whether it uses weak password and account policies, (4) whether it stores configuration secrets in clear text, (5) whether it can transfer files, (6) whether the application is known to propagate malware, (7) whether the application is purposely evasive, (8) whether the application has known vulnerabilities, etc. In some embodiments, the threat detector is a third-party whitelisting application, such as the Bit9.

The context engine in some embodiments provides the threat level indicator produced by the threat detector 132 to one or more service engines as another contextual attribute for performing services on a new process event or the data messages of a new network event; a service engine can use the threat level indicator as another attribute to identify service rules to enforce.

The context engine 110 stores the contextual attributes that it collects for network events and process events in the attribute storage 145. In some embodiments, the context engine stores each set of contextual attributes with one or more network event identifiers and/or process identifiers. For example, in some embodiments, the context engine 110 stores the collected contextual attributes for a new process event with the process identifier, or with a reference to this identifier. The context engine then uses the process identifier to provide the collected context attributes to a service engine (e.g., the process control engine 122) that performs a service for the process event.

The context engine in some embodiments stores the collected context attributes for a new network connection event with the five-tuple identifier of the network connection event, or with a reference to this five-tuple identifier. In some of these embodiments, the context engine provides to a service engine the context attributes for a network event along with this event's five-tuple identifier. The data messages for this network event will use this five-tuple identifier, and hence the service engine can use the supplied five-tuple identifier to identify the context attributes associated with a data message flow.

The context engine employs a push model in some embodiments to distribute the collected contextual attributes to the service engines 130, employs a pull model in other embodiments to distribute these attribute to the service engines 130, while in other embodiments, employing a push model for some service engines and a pull model for other service engines. In the push model, the context engine in some embodiments distributes to a service engine the contextual attributes that it collects for a process event or a network event with the process's identifier and/or the network event's flow identifier (e.g., the flow's five-tuple identifier).

In some embodiments, the context engine distributes to the service engine only the contextual attributes that are relevant for that service engine's service rules. In other words, in these embodiments, the context engine compares each collected attribute in a set of collected attributes (e.g., for a network event or a process event) with a list of attributes used by a service engine's service rules, and discards each collected attribute that is not used by the service rules. The context engine then provides to the service engine only the subset of collected attributes (in the set of collected attributes) that is being used by the engine's service rules. In other embodiments, the service engines perform this filtering operation to discard the contextual attributes that are not needed.

In the pull model, the context engine receives queries from a service engine for the contextual attributes that the context engine has collected for a particular process or network connection. In some embodiments, the context engine receives a process ID or a flow identifier (e.g., five-tuple identifier) with a query from the service engine, and uses the received identifier to identify the attribute set that it has to provide to the service engine.

In some embodiments, the context engine generates a service token (also called a service tag) for the collection of attributes that are relevant for the service engine, and provides this service token to another module (e.g., the GI agent or another module on the host) to pass along to the service engine (e.g., pass along in a data message's encapsulating tunnel header). The service engine then extracts the service token and provides this service token to the context engine in order to identify the contextual attributes that the context engine has to provide to the service engine.

In some embodiments, the context engine 110 and the service engines 130 are all kernel space components of a hypervisor on which multiple VMs or containers execute, as further described below by reference to FIG. 2. In other embodiments, the context engine and/or one or more service engines are user space processes. For example, one or more service engines in some embodiments are service VMs (SVMs). In some embodiments, one or more service engines are in ingress datapaths and/or egress datapaths of DCNs, in order to receive access to data message flows to and from the DCNs to perform services on these data message flow. In other embodiments, one or more other modules on the host 100 intercept data messages from the ingress/egress datapaths and forward these messages to one or more service engines for these engines to perform services on the data messages. One such approach will be described below by reference to FIG. 2.

Different embodiments use different types of context-based service engines. In the example illustrated in FIG. 1, the service engines 130 include the discovery engine 120, the process control engine 122, the encryption engine 124, the load balancer 126 and the firewall engine 128. Each of these service engines 130 has an attribute-based, service-rule storage. FIG. 1 collectively represents all the context-based, service-rule storages of these service engines with the context-based service rule storage 140 in order to simplify the illustration that is presented in this figure.

In some embodiments, each service rule in the context-based service rule storage 140 has a rule identifier for matching to a process or flow identifier to identify the rule to enforce for a process or network event. In some embodiments, the context-based service rule storage 140 is defined in a hierarchical manner to ensure that a rule check will match a higher priority rule before matching a lower priority rule. Also, in some embodiments, the context-based service rule storage 140 contains a default rule that specifies a default action for any rule check, as further explained below.

The firewall engine 128 performs firewall operations on data messages sent by or received for the DCNs 105. These firewall operations are based on firewall rules in the context-based service rule storage 140. Some of the firewall rules are defined purely in terms of layer 2-layer 4 attributes, e.g., in terms of five-tuple identifiers. Other firewall rules are defined in terms of contextual attributes that can include one or more of the collected contextual attributes, such as application names, application versions, AppID, resource consumption, threat level, user ID, group ID, etc. Yet other firewall rules in some embodiments are defined in terms of both L2-L4 parameters and contextual attributes. As the firewall engine 128 can resolve firewall rules that are defined by reference to contextual attributes, this firewall engine is referred to as a context-based firewall engine.

In some embodiments, the context-based firewall engine 128 can allow, block or re-route data message flows based on any number of contextual attributes, because its firewall rules can be identified in terms of any combination of the collected contextual attributes. For example, this firewall engine can block all email traffic from chrome.exe when the user is part of a Nurse user group, when one firewall rule specifies that data messages should be blocked when the flow is associated with the Nurse group ID, the AppID identifies the traffic type as email, and the application name is Chrome. Similarly, context based firewall rules can block data message flows associated with video conferences, online video viewing, or use of old versions of software. Examples of such rules would block all Skype traffic, block all YouTube video traffic, block all HipChat audio/video conferences when application version number is older than a particular version number, block data message flows for any application with a high threat score, etc.

The load balancing engine 126 performs load balancing operations on data messages sent by the DCNs 105 to distribute the data message flows to different destination or service nodes in one or more destination/service node clusters. These load balancing operations are based on load-balancing rules in the context-based service rule storage 140. In some of these embodiments, each load-balancing rule can specify one or more load balancing criteria (e.g. a round robin criterion, a weighted round-robin criteria, etc.) for distributing traffic, and each criteria can be limited to a particular time range. In some embodiments, a load balancing operation involves replacing a data message flow's destination network address (e.g., the destination IP address, the destination MAC address, etc.).

Some of the load-balancing rules are defined purely in terms of L2-L4 attributes, e.g., in terms of five-tuple identifiers. Other load-balancing rules are defined in terms of contextual attributes that can include one or more of the collected contextual attributes, such as application names, application versions, AppID, resource consumption, threat level, user ID, group ID, etc. Yet other load-balancing rules in some embodiments are defined in terms of both L2-L4 parameters and contextual attributes. As the load balancing engine 126 can resolve load-balancing rules that are defined by reference to contextual attributes, this load balancing engine is referred to as a context-based load balancer.

In some embodiments, the context-based load balancer 126 can distribute the data message flows based on any number of contextual attributes, because its load-balancing rules can be identified in terms of any combination of the collected contextual attributes. For example, the data distribution of the load balancer 126 can be based on any combination of user and application data. Examples of such load balancing operations include: (1) distributing data message flows associated with the Finance department on all load balancing pools, (2) redirecting all the Finance department's traffic to another pool when the primary pool for this department is down to make this department's traffic highly available, (3) making all traffic associated with the Doctor's user group highly available. In some embodiments, the load-balancing rules can also be defined in terms of collected resource consumption, in order to distribute traffic to provide more or less resources to applications that consume a lot of resources on the DCNs.

The encryption engine 124 performs encryption/decryption operations (collectively referred to as encryption operations) on data messages sent by or received for the DCNs 105. These encryption operations are based on encryption rules in the context-based service rule storage 140. In some embodiments, each of these rules includes an encryption/decryption key identifier, which the encryption engine can use to retrieve an encryption/decryption key from a key manager on the host or operating outside of the host. Each encryption rule also specifies in some embodiments the type of encryption/decryption operation that the encryption module has to perform.

Each encryption rule also has a rule identifier. For some encryption rules, the rule identifiers are defined purely in terms of L2-L4 attributes, e.g., in terms of five-tuple identifiers. Other encryption rules are defined in terms of contextual attributes that can include one or more of the collected contextual attributes, such as application names, application versions, AppID, resource consumption, threat level, user ID, group ID, etc. Yet other encryption rules in some embodiments are defined in terms of both L2-L4 parameters and contextual attributes. As the encryption engine 124 can resolve encryption rules that are defined by reference to contextual attributes, this encryption engine is referred to as a context-based encryption engine.

In some embodiments, the context-based encryption module 124 can encrypt or decrypt the data message flows based on any number of contextual attributes because its encryption rules can be identified in terms of any combination of the collected contextual attributes. For example, the encryption/decryption operation of the encryption engine 124 can be based on any combination of user and application data. Examples of such encryption operations include: (1) encrypt all traffic from Outlook (started on any machine) to Exchange Server, (2) encrypt all communication between applications in a three tier Web server, Application Server and Database Server, (3) encrypt all traffic originating from the Administrators Active Directory group, etc.

The process control engine 122 enforces context-based process control operations (e.g., process assessment and termination operations) on processes started on the DCNs 105. In some embodiments, whenever the context engine 110 receives a new process event from a GI agent 150 of a DCN, it provides the process parameters associated with this process event to the process control engine 122. This engine then uses the received set of process parameters to examine its context-based service rule storage 140 to identify a matching context-based, process-control rule.

The process control engine 122 can direct the context engine to direct the GI agent of the DCN to perform a process-control operation on a process. Examples of such process-control operations include (1) terminating a video conference application that has a particular version number, (2) terminating a browser that is displaying YouTube traffic, (3) terminating applications that have a high threat level score.

The discovery engine 120 is another context-based service engine. In some embodiments, the discovery engine 120 captures new process events and new network events from the context engine, along with the contextual attributes that the context engine collects for these process and network events. As further described below, the discovery service engine then relays these events and their associated contextual attributes to one or more network managers (e.g., servers) that provide a management layer that allows network administrators to visualize events in a datacenter and specify policies for compute and network resources in the datacenter.

In relaying these events and attributes to the network management layer, the discovery module of some embodiments performs some pre-processing of these events and attributes. For example, in some embodiments, the discovery module filters some of the network or process events, while aggregating some or all of these events and their attributes. Also, in some embodiments, the discovery engine directs the context engine to collect additional contextual attributes for process or network events through the GI agents or other modules (e.g., the DPI engine or threat detection engine), or to capture other types of events, such as file events and system events.

For example, in some embodiments, the discovery engine directs the context engine to build an inventory of the applications installed on the machines, and to periodically refresh this inventory. The discovery engine might so direct the context engine at the request of the management plane, or based on operational configurations that the management or control plane specifies for the discovery engine. In response to the request from the discovery engine, the context engine in some embodiments has each GI agent on each of its host's machine discover all installed processes on the machine, and all running processes and services.

After building an inventory of installed applications and the running processes/services, the discovery engine of a host computer in a datacenter provides this information to the network/compute managers in the management plane. In some embodiments, the management plane collects contextual attributes from sources other than the host computer discovery and context engines. For instance, in some embodiments, the management place collects from one or more servers compute context (e.g., cloud context from cloud vendors, or compute virtualization context by datacenter virtualization software), identity context from directory service servers, mobility context from mobility management servers, endpoint context from DNS (domain name server) and application inventory servers, network context (e.g., virtual network context from network virtualization server), etc.

By collecting the contextual information (e.g., information from the discovery and context engines and/or information from other context sources), the management plane can provide a user interface to the network/compute administrators to visualize the compute and network resources in the datacenter. Moreover, the collected contextual attributes allow the management plane to provide controls through this user interface for these administrators to specify context-based service rules and/or policies. These service rules/policies are then distributed to the host computers so that service engines on these computers can perform context-based service operations.

In some embodiments described above, the same service engine 130 (e.g., the same firewall engine 128) performs the same type of service (e.g., a firewall service) based on service rules that can be defined in terms of message flow identifiers (e.g., five-tuple identifiers) or in terms of collected contextual attributes (e.g., AppID, threat level, user identifier, group identifier, application name/version, etc.) associated with the data message flows. In other embodiments, however, different service engines provide the same type of service based on the message flow identifiers (e.g., five-tuple identifiers) and based the collected contextual attributes of the data message flows. For instance, some embodiments use one flow-based firewall engine that performs firewall operations based on rules defined in terms of flow identifiers, and another context-based firewall engine that performs firewall operations based on rules defined in terms of context attributes (e.g., AppID, threat level, user identifier, group identifier, application name/version, etc.).

FIG. 2 illustrates a more-detailed example of a host computer 200 that in some embodiments is used to establish a distributed architecture for configuring and performing context-rich, attribute-based services in a datacenter. This host computer 200 includes many of the same components as host computer 100, such as context engine 110, service engines 130, threat detector 132, DPI module 135, context-based service rule storage 140, and context-attribute storage 145. Like in FIG. 1, the service engines 130 in FIG. 2 include the discovery engine 120, the process control engine 122, the encryption engine 124, the load balancer 126 and the firewall engine 128.

In FIG. 2, the DCNs are VMs 205 that execute on a hypervisor. Also, in FIG. 2, the host computer 200 includes a software forwarding element 210, an attribute-mapping storage 223, a connection state cache storages 225, a MUX (multiplexor) 227, and a context-engine policy storage 143. In some embodiments, the context engine 110, the software forwarding element 210, the service engines 130, the context-based service rule storages 140, the connection state cache storage 225, the context-engine policy storage 143, and the MUX 227 are in the kernel space of the hypervisor, while the VMs 205 are in the hypervisor's user space. In other embodiments, one or more service engines are user space modules (e.g., are service VMs).

In some embodiments, the VMs 205 serve as data end points in the datacenter. Examples of such machines include webservers, application servers, database servers, etc. In some cases, all the VMs belong to one entity, e.g., an enterprise that operates the host. In other cases, the host executes in a multi-tenant environment (e.g., in a multi-tenant data center), and different VMs may belong to one tenant or to multiple tenants.

Each VM 205 includes a GI agent 250 that interacts with the context engine 110 to provide context attribute sets to this engine, and to receive instructions and queries from this engine. The interactions between the GI agents 250 and the context engine 110 are similar to the interactions described above between the GI agents 150 and the context engine 110. However, as shown in FIG. 2, all the communication between the context engine 110 and the GI agents 250 in some embodiments are relayed through the MUX 227. One example of such a mux is the mux that is used by the Endpoint Security (EPSec) platform of ESX hypervisors of VMware, Inc.

In some embodiments, the GI agents communicate with the MUX 227 through a fast communication channel (such as VMCI channel of ESX). In some embodiments, this communication channel is a shared memory channel. As mentioned above, the attributes collected by the context engine 110 from the GI agents 250 in some embodiments include a rich group of parameters (e.g., layer 7 parameters, process identifiers, user identifiers, group identifiers, process name, process hash, loaded module identifiers, consumption parameters, etc.)

As shown, each VM 205 also includes a virtual network interface card (VNIC) 255 in some embodiments. Each VNIC is responsible for exchanging messages between its VM and the software forwarding element (SFE) 210. Each VNIC connects to a particular port of the SFE 210. The SFE 210 also connects to a physical network interface card (NIC) (not shown) of the host. In some embodiments, the VNICs are software abstractions created by the hypervisor of one or more physical NICs (PNICs) of the host.

In some embodiments, the SFE 210 maintains a single port 260 for each VNIC of each VM. The SFE 210 connects to the host PNIC (through a NIC driver (not shown)) to send outgoing messages and to receive incoming messages. In some embodiments, the SFE 210 is defined to include a port 265 that connects to the PNIC's driver to send and receive messages to and from the PNIC. The SFE 210 performs message-processing operations to forward messages that it receives on one of its ports to another one of its ports. For example, in some embodiments, the SFE tries to use data in the message (e.g., data in the message header) to match a message to flow based rules, and upon finding a match, to perform the action specified by the matching rule (e.g., to hand the message to one of its ports 260 or 265, which directs the message to be supplied to a destination VM or to the PNIC).

In some embodiments, the SFE 210 is a software switch, while in other embodiments it is a software router or a combined software switch/router. The SFE 210 in some embodiments implements one or more logical forwarding elements (e.g., logical switches or logical routers) with SFE executing on other hosts in a multi-host environment. A logical forwarding element in some embodiments can span multiple hosts to connect VMs that execute on different hosts but belong to one logical network.

Different logical forwarding elements can be defined to specify different logical networks for different users, and each logical forwarding element can be defined by multiple software forwarding elements on multiple hosts. Each logical forwarding element isolates the traffic of the VMs of one logical network from the VMs of another logical network that is serviced by another logical forwarding element. A logical forwarding element can connect VMs executing on the same host and/or different hosts. In some embodiments, the SFE extracts from a data message a logical network identifier (e.g., a VNI) and a MAC address. The SFE in these embodiments uses the extracted VNI to identify a logical port group, and then uses the MAC address to identify a port within the port group.

Software switches (e.g., software switches of hypervisors) are sometimes referred to as virtual switches because they operate in software and they provide the VMs with shared access to the PNIC(s) of the host. However, in this document, software switches are referred to as physical switches because they are items in the physical world. This terminology also differentiates software switches from logical switches, which are abstractions of the types of connections that are provided by the software switches. There are various mechanisms for creating logical switches from software switches. VXLAN provides one manner for creating such logical switches. The VXLAN standard is described in Mahalingam, Mallik; Dutt, Dinesh G.; et al. (May 8, 2013), VXLAN: A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks, IETF.

The ports of the SFE 210 in some embodiments include one or more function calls to one or more modules that implement special input/output (I/O) operations on incoming and outgoing messages that are received at the ports. Examples of I/O operations that are implemented by the ports 260 include ARP broadcast suppression operations and DHCP broadcast suppression operations, as described in U.S. patent application Ser. No. 14/070,360, filed Nov. 1, 2013, now issued as U.S. Pat. No. 9,548,965. Other I/O operations (such as firewall operations, load balancing operations, network address translation operations, etc.) can be so implemented in some embodiments of the invention. By implementing a stack of such function calls, the ports can implement a chain of I/O operations on incoming and/or outgoing messages in some embodiments. Also, in some embodiments, other modules in the data path (such as the VNICs 255, port 265, etc.) implement the I/O function call operations, instead of, or in conjunction with, the ports 260.

In some embodiments, one or more of function calls of the SFE ports 260 can be to one or more service engines 130 that process context-based service rules in the context-based service rule storages 140. Each service engine 130 in some embodiments has its own context-based service rule storage 140, attribute-mapping storage 223, and connection state cache storage 225. FIG. 2 presents just one context-based service rule storage 140, attribute-mapping storage 223, and connection state cache storage 225 for all the service engines in order not to obscure the presentation in this figure with unnecessary detail. Also, in some embodiments, each VM has its own instance of each service engine 130 (e.g., its own instance of discovery engine 120, process control engine 122, encryption engine 124, load balancer 126, and firewall engine 128). In other embodiments, one service engine can service data message flows for multiple VMs on a host (e.g., VMs for the same logical network).

To perform its service operation for a data message flow, a service engine 130 in some embodiments tries to match the flow identifier (e.g., the five-tuple identifier) and/or the flow's associated context attribute set to the rule identifiers of its service rules in its context-based service rule storage 140. Specifically, for a service engine 130 to perform its service check operation for a data message flow, the SFE port 260 that calls the service engine supplies a set of attributes of a message that the port receives. In some embodiments, the set of attributes are message identifiers, such as traditional five-tuple identifiers. In some embodiments, one or more of the identifier values can be logical values that are defined for a logical network (e.g., can be IP addresses defined in a logical address space). In other embodiments, all of the identifier values are defined in the physical domains. In still other embodiments, some of the identifier values are defined in the logical domain, while other identifier values are defined in the physical domain.

The service engine in some embodiments then uses the received message's attribute set (e.g., the message's five-tuple identifier) to identify the context attribute set that the service engine has stored for this flow in the attribute-mapping storage 223. As mentioned above, the context engine 110 in some embodiments supplies the context attributes for new flows (i.e., new network connection events) and for new processes to the service engines 130, along with a flow identifier (e.g., a five-tuple identifier) or a process identifier. The context-engine policy storage 143 contains the rules that control the operation of the context engine 110. In some embodiments, these policies direct the context engine to generate rules for the service engines or to direct the service engines to generate rules (e.g., when a high-threat application runs on a VM, directing the encryption engine for all the other VMs on the same host to encrypt their data message traffic). The service engines 130 in these embodiments store the context attributes that they receive from the context engine in the attribute-mapping storage 223.

In some embodiments, a service engine 130 stores the context attribute set for each new flow or new process with that flow's identifier (e.g., five-tuple identifier) or that process' identifier in the attribute-mapping storage. In this manner, the service engine can identify the context attribute set for each new flow that it receives from the SFE ports 260 by searching its attribute-mapping storage 223 for a context record that has a matching flow identifier. The context record with the matching flow identifier includes the context attribute set for this flow. Similarly, when identifying the context attribute set for a process event, a service engine in some embodiments searches its attribute-mapping storage 223 for a context record with a matching process identifier.

As mentioned above, some or all of the service engines in some embodiments pull the context attribute sets for a new flow or new process from the context engine. For instance, in some embodiments, a service engine supplies a new flow's five-tuple identifier that it receives from the SFE port 260, to the context engine 110. This engine 110 then examines its attribute storage 145 to identify a set of attributes that is stored for this five-tuple identifier, and then supplies this attribute set (or a subset of it that it obtains by filtering the identified attribute set for the service engine) to the service engine.

As described above, some embodiments implement the pull model by using a service token to encode the attribute set for a new message flow. When notified of a new network connection event, the context engine 110 in some embodiments (1) collects the context attribute set for the new event, (2) filters this set to discard the attributes that are not relevant for performing one or more services on the flow, (3) stores the remaining filtering attribute subset in the attribute storage 145 along with a service token, (4) provides the service token to the GI agent, which causes this token to be passed to the service engine(s) in-band (e.g., tunnel header) or out-of-band. When the service engine gets the new flow through the SFE port 260, it supplies this flow's service token to the context engine, which uses this service token to identify in its attribute storage 145 the context attributes to supply to the service engine. In the embodiments that the SFE port does not provide this service token to the service engine, the service engine first has to identify the service token by searching its data stores using the flow's identifier before supplying the service token to the context engine.

After identifying the contextual attribute set for a data message flow, the service engine 130 in some embodiments performs its service operation based on service rules that are stored in the context-based service rule storage 140. To perform its service operation, the service engine 130 matches the received attribute subset with corresponding attribute sets that are stored for the service rules. In some embodiments, each service rule in the context-based service rule storage 140 has a rule identifier and an action parameter set. As mentioned above, the rule identifier of a service rule in some embodiments can be defined in terms of one or more contextual attributes that are not L2-L4 header parameters (e.g., are L7 parameters, process identifiers, user identifiers, group identifiers, process name, process hash, loaded module identifiers, consumption parameters, etc.). In some embodiments, a rule identifier can also include L2-L4 header parameters. Also, in some embodiments, one or more parameters in a rule identifier can be specified in terms of an individual value or a wildcard value. Also, in some embodiments, a rule identifier can include a set of individual values or a group identifier, such as a security group identifier, a compute construct identifier, a network construct identifier, etc.

To match a received attribute set with the rules, the service engine compares the received attribute set with the associated identifiers of the service rules stored in the context-based service rule storage 140. Upon identifying a matching rule, the service engine 115 performs a service operation (e.g., a firewall operation, a load balancing operation, an encryption operation, other middlebox operation, etc.), based on the action parameter (e.g., based on Allow/Drop parameter, the load balancing criteria, encryption parameters, etc.) of the matching rule

In some embodiments, the context-based service rule storage 140 is defined in a hierarchical manner to ensure that a message rule check will match a higher priority rule before matching a lower priority rule, when the message's attribute subset matches multiple rules. Also, in some embodiments, the context-based service rule storage 140 contains a default rule that specifies a default action for any message rule check that cannot identify any other service rules; this default rule will be a match for all possible attribute subsets in some embodiments, and ensures that the service rule engine will return an action for all received attribute subsets. In some embodiments, the default rule will specify no service.

Multiple messages can have the same message identifier attribute sets, e.g., when the messages are part of one flow that is associated with one communication session between two machines. Accordingly, after matching a data message with a service rule in the context-based service rule storage 140 based on the message's identified context attribute set, the service engine of some embodiments stores the service rule (or a reference to the service rule) in the connection state cache storage 225, so that it can later use this service rule for subsequent data messages of the same flow.

In some embodiments, the connection state cache storage 225 stores the service rule, or a reference to the service rule, that the service engine 130 identifies for different message identifier sets (e.g., for different five-tuple identifiers that identify different data message flows). In some embodiments, the connection state cache storage 225 stores each service rule, or reference to the service rule, with an identifier (e.g., a flow's five-tuple identifier and/or a hash value of the flow's five-tuple identifier) that is generated from the matching message identifier set.

Before checking with the context-based service rule storage 140 for a particular message, the service rule engine 130 of some embodiments checks the connection state cache storage 225 to determine whether this storage has previously identified a service rule for this message's flow. If not, the service engine 130 identifies the contextual attribute set for the message flow, and then checks the context-based service rule storage 140 for a service rule that matches the message's identified attribute set and/or its five-tuple identifier. When the connection state data storage has an entry for the particular message, the service engine performs its service operation based on this service rule's action parameter set.

In the service architecture of FIG. 2, the DPI module 135 performs deep packet inspection on a data message flow at the direction of the firewall engine 128. Specifically, when the firewall engine 128 receives a new data message that is part of a new data message flow, the firewall engine in some embodiments directs the DPI module to inspect that new data message and one or more of the next few data messages in the same flow. Based on this examination, the DPI engine identifies the type of traffic (i.e., the application on the wire) that is being sent in this data message flow, generates an AppID for this traffic type, and stores this AppID in the attribute storage 145. In some embodiments, the context attribute sets are stored in the attribute storage based on flow identifiers and/or process identifier. Accordingly, in some embodiments, the DPI engine 135 stores the AppID for a new data message flow in the attribute storage 145 based on that flow's five-tuple identifier.

In some embodiments, the context engine 110 pushes to the service engines 130 the AppID for a new data message flow once the DPI engine stores the AppID in the attribute storage 145. In other embodiments, the context engine 110 pulls the AppID from the attribute storage 145 whenever it is queried for the contextual attributes for a data message flow by a service engine, again by using the five-tuple identifier of the flow to identify the record in the attribute storage 145 with the matching record identifier and the AppID.

FIG. 3 illustrates a process 300 that the context engine performs 110 in some embodiments each time it is notified about a new process or network-connection event. From a GI agent 250 of a VM 205, the process 300 initially receives (at 305) a notification regarding a new process or network connection event. Next, at 310, the process 300 collects all the desired contextual attributes regarding the notified event.

As described above, the context engine 110 interacts with the reporting GI agent 250 to collect additional information regarding a reported event. The GI agent in some embodiments interacts with the network stack and/or process subsystem in the VM's OS kernel space to collect contextual attributes regarding a process or network event. The GI agent in some embodiments also collects this information from user-space modules (e.g., a user mode DLL) that operate in user-space process (e.g., a VMtool.exe) to collect contextual attributes. On VM's using Microsoft Windows, the GI agent registers hooks in the Windows Filtering Platform (WFP) to obtain network events, while registering in the Window's Process Subsystem to collect process related attributes. In some embodiments, the GI agent hook is at the Application Layer Enforcement (ALE) layer of WFP, so that it can capture all socket-connection requests from application processes on the VM.

In some embodiments, the context engine 110 interacts with the management or control plane to collect contextual attributes, and/or to receive records that it can examine to identify contextual attributes for identified network or process events. In some of these embodiments, the context engine interacts with a management or control plane proxy (that operates on its host) in order to obtain data from the management or control plane compute devices that operate outside of the host. In some of these embodiments, the context engine operates in the kernel space.

After collecting the contextual attributes at 310, the process uses (at 315) the attributes of the received event or the contextual attributes collected for the received event to identify one or more policies in the context-engine policy storage 143. At 315, the process identifies any policy that has a policy identifier that matches the collected attributes and event attributes. Next, at 320, the process produces context-attribute mapping records for one or more service engines based on the policies identified at 315. One or more of the identified policies might specify that for a particular process or network event, a particular set of service engines need to be notified about the event (e.g., about a new data message flow), with each service engine receiving a subset of contextual attributes that are relevant for that service engine to perform its processing for that event. This operation in some embodiments involves the context engine not including attributes that are not relevant for each particular service engine in the subset of contextual attributes that it provides to that particular service engine.

In some embodiments, certain events might necessitate new service rules to be created for one or more service engines. For example, when a high-threat application is identified on one VM, a policy might specify that other VMs on that host might have to start to encrypt their data message traffic. In some such embodiments, the context-engine policy storage 143 includes policies that direct the context engine to generate service rules for service engines under certain circumstances, or to direct the service engines to generate such service rules. For such embodiments, the process (at 320), if needed generates service rules for service engines under certain circumstances, or directs the service engines to generate such service rules

At 325, the process 300 distributes the mapping records and/or generated service rules/instructions to one or more service engines. As mentioned above, the context engine can employ a push model or a pull model to distribute such records and/or rules/instructions. When employing a pull model, the process 300 in some embodiments not only performs the operation 325 in response to a query from a service engine, but also performs some or all of the operation 320 in response to this query. After 325, the process ends.

In some embodiments, the service engines can differentiate the data message flows for two different processes that run concurrently on a VM for two different login/administrative credentials because the context engine collects the user and group identifiers for each data message flow when each flow starts, and associates each flow with its user and group identifiers. FIG. 4 illustrates a process 400 that the context engine performs to collect the user and group identifiers each time it receives a new network connection event from a GI agent.

The process 400 initially receives (at 405) a notification of a new network connection event from a GI agent 250 on a VM 205. As mentioned above, the GI agent in some embodiments provides the following information in a new network connection notification: the connection's five-tuple identifier, the identifier of the process requesting the network connection, a user identifier associated with the requesting process, and a group identifier associated with the requesting process.

Next, at 410, the process 400 queries the GI agent to collect any other contextual attributes needed for the new network connection event. Examples of such additional parameters include additional parameters associated with the process requesting the network connection. At 415, the process 400 then publishes one or more context attribute records to one or more service engines. In some embodiments, each context attribute record to each service engine includes the connection's five-tuple identifier and a set of one or more context attributes, including the user identifier and/or the group identifier. The service engines then store the provided contextual attribute records in their attribute-mapping storages 223, so that they can use these records to identify the context attribute sets associated with different data message flows that they process. For service engines that have different service rules for different processes concurrently running on a VM for different user accounts, the context attribute sets include a user identifier or a group identifier to allow these service engines to associate different data message flows from the VM to different user/group identifiers.

In some embodiments, the context engine does not include in a service engine's context attribute record the contextual attributes that are not needed by the service engine. Also, in some embodiments, the context engine provides different context attribute records to different context engines for the same network connection event, because different service engines need different sets of context attributes. As described above, the context engine 110 in some embodiments does not push the context attribute sets for new network connections to some or all of the service engines, but rather has these service engines pull these attribute sets.

In some embodiments, the context engine can associate a data message flow on a source host with the source VM (i.e., the VM that is the source of the data message flow) with a contextual attribute of a destination VM on the same host or a different destination host. The firewall engine 128 in these embodiments can then use such destination-based contextual attributes to resolve firewall rules. For instance, the firewall engine can drop all data messages addressed to a particular type of server (e.g., a Sharepoint server). To support such destination-based rules, the context engines of some embodiments directs the GI agents to identify the processes that register for notifications on particular ports, and uses this information along with process identifiers and hashes to identify the applications that serve as destinations of data message flows. The information collected by the context engines on the different hosts are collected by the management plane, which aggregates this data and distributes the aggregated data to the other context engines. The distributed information can then be used by the context engines on the host to resolve contextual policies on these hosts, in order to supply context-based rules to the context-based service engines on these hosts.

The encryption engine 124 is a context-based encryptor that performs its encryption/decryption operations based on encryption rules that can be specified in terms of not only L2-L4 parameters, but also in terms of contextual attributes. FIG. 5 illustrates an example of such context-based encryption rules. These rules are used independently by different encryption engines 124 on different hosts 200 to encrypt data messages sent by and received for the VMs 205 on these hosts. In this manner, the encryption engines 124 that enforce the same encryption rules on the different hosts (e.g., for one tenant or one logical network) collectively form a distributed encryption engine (i.e., a single, conceptual logical encryption engine) that spans across the multiple hosts to uniformly perform a desired set of encryption and decryption In some embodiments, each VM 205 has its own encryption engine, while in other embodiments, one encryption engine 124 can service multiple VMs 205 on the same host (e.g., multiple VMs for the same tenant on the same host).

FIG. 5 illustrates an encryption rule data store 140 that stores several encryption rules. Each encryption rule includes (1) a rule identifier 505, (2) an encryption type identifier 510, and (3) a key identifier 515. Each rule identifier 505 specifies one or more data tuples that can be used to identify a rule that matches a data message flow. In some embodiments, a rule identifier can include any L2-L4 parameters (e.g., source IP address, source port, destination port, destination IP, protocol, etc.). These L2-L4 parameters in some embodiments can be defined in the physical domain or logical domain. Also, as shown, the rule identifier can include contextual attributes, such as AppID, application name, application version, user ID, group ID, threat level, resource consumption.

In some embodiments, an encryptor 124 searches an encryption rule data store 140 by comparing one or more message attributes (e.g., five-tuple header values, contextual attributes) with the rule identifiers 505 to identify the highest priority rule with a matching rule identifier. Also, in some embodiments, the encryption rule data store 140 has a default rule that is used when no other rule matches a data message flow. In some embodiments, the default rule specifies no encryption key as no rule exists for encrypting the data message flow. Also, in some embodiments, when the default rule is returned to the encryptor 124, the encryptor 124 does not encrypt the data message flow for which it is performing the check.

The encryption type 510 of each encryption rule specifies the type of encryption/decryption to use, while the key identifier 515 of each rule identifies the key to use for the encryption/decryption. In some embodiments, the encryption rules only specify the key identifiers 515 and do not specify the encryption types 510, because the key identifiers identify both the key and the type of encryption/decryption or these types are otherwise specified (e.g., preconfigured) in the encryptor.

The encryption and decryption operations of the encryption engine 124 will now be described by reference to FIGS. 6-8. In some embodiments, the encryption and decryption operations use the same key or transposed versions of the same key, because these embodiments use a symmetric encryption scheme in which the same key is used to encrypt and decrypt the message, or transposed versions of the same key are used to encrypt and decrypt the message. Other embodiments use asymmetric encryption schemes (e.g., source encryptor using its private key, and the destination encryptor using the public key of the source encryptor).

FIG. 6 illustrates a process 600 that the encryptor 124 performs to encrypt a data message sent by a VM 205 on the host 200. As shown, the process 600 starts when the encryptor 124 receives (at 605) a data message from its corresponding SFE port 260. This port relays this message when it receives the data message from its VM. In some embodiments, the port relays the data message by passing to the encryptor a reference (e.g., a handle that identifies a location in memory that stores the data message) to the data message or the data message's header values.

Next, at 610, the encryptor determines whether its connection state cache 225 stores a cached encryption record for the received data message. In some embodiments, each time an encryptor finds an encryption rule for a VM data message in some embodiments, it creates a cached encryption record that either stores the encryption rule, a reference to the encryption rule, the encryption key, or the encryption key's identifier in the connection state cache 225.

The encryptor creates this cache record so that when it receives another data message for the same data message flow, the encryptor does not have to search the encryption rule data store 140 to identify an encryption rule for the subsequently received data messages in the same flow. In some embodiments, each cached record in the connection state cache 225 has a record identifier that is defined in terms of data message identifiers (e.g., five-tuple identifiers). In these embodiments, the process 600 compares the received data message's identifier (e.g., five-tuple identifier) with the record identifiers of the cached records to identify any record with a record identifier that matches the received data message's identifier.

When the process 600 identifies (at 610) a cached encryption record for the received data message is in the connection state cache 225, the process (at 615) then uses the key identified by the identified encryption records to encrypt the received data message. In the embodiments where the cached record contains the encryption rule or a reference to the encryption rule, the process 600 retrieves a key identifier from the stored or referenced rule and uses this identifier to retrieve a key from a key data store that is stored on the host 200 or from a key manager on the host or operating outside of the host. Similarly, in the embodiments where the cached record contains the key identifier, the process 600 retrieves a key identifier from the cached record and uses this identifier to retrieve a key from the local or remote key data store.

In some embodiments, the process encrypts (at 615) the data message's payload (e.g., the L2 payload) by using the identified encryption key, while generating an integrity check value (ICV) hash of the payload and some or all of the header values (e.g., the physical L3 and L4 header values and/or logical L2 or L3 header values), so that the message's destination would have (1) to decrypt the encrypted portion of the data message, and (2) to verify the authenticity and integrity of the payload and header values that were used for the ICV calculation.

For some or all of the data messages, the encryption process 600 in some embodiments also encrypts (at 615) a portion of the data message header. For data messages that are exchanged between machines associated with a logical network, some embodiments encrypt all of the physical header values of the data message. Some of these embodiments perform ICV operation on the logical network identifier (e.g., the VNI) and the payload so that the decryptor at the destination host can verify the authenticity and integrity of the encrypted data message.

After encrypting the data message, the process (at 615) sends the encrypted data message along its datapath. In some embodiments, this operation entails returning a communication to the SFE port 260 (that called the encryptor to initiate the process 600) to let the port know that the encryptor is done with its processing of the data message. The SFE port 260 can then handoff the data message to the SFE 210 or can call another I/O chain operator to perform another operation on the data message. After 615, the process 600 ends.

When the process 600 determines (at 610) that the connection state cache 225 does not store any cached record that matches the received data message, the process 600 identifies (at 620) one or more contextual attributes for this data message flow. As mentioned above, the service engines of different embodiments perform this operation differently. For instance, in some embodiments, the encryption engine 124 checks the attribute-mapping storage 223 for a record that has a record identifier that matches the received data message's header values (e.g., its five-tuple identifier). It then uses (at 620) the contextual attribute set of this matching record as the contextual attribute set of the received data message flow.

In other embodiments, the encryption engine 124 queries the context engine 110 to obtain the contextual attribute set for the received data message. With this query, the encryption engine supplies the received message's flow identifier (e.g., five-tuple identifier) or its associated service token, which the context engine then uses to identify a set of contextual attributes in its context attribute storage 145, as explained above.

Once the process 600 has obtained the contextual attribute set for the received data message, it uses this attribute set by itself or along with the message's other identifiers (e.g., five-tuple identifiers) to identify (at 625) an encryption rule in the encryption rule data store 140 that matches the received data message's attributes. For instance, in some embodiments, the encryption rules have rule identifiers that are defined in terms of one or more of non-contextual attributes (e.g., five-tuple attributes, logical attributes, etc.) and/or one or more contextual attributes, such as application name, application version, user ID, group ID, AppID, threat level, resource consumption level, etc. To identify the encryption rule in the encryption rule data store 140, the process in some embodiments compares contextual attributes and/or other attributes (e.g., five-tuple identifier) of the received data message with the rule identifiers (e.g., rule identifiers 505) of the encryption rules to identify the highest priority rule that has an identifier that matches the message's attribute set.

After 625, the process determines (at 630) whether it identified an encryption rule that specifies that the received data message should be encrypted. As mentioned above, the encryption rule data store 140 has a default encryption rule that matches all data message, and is returned when no other encryption rule matches a received data message. The default encryption rule in some embodiments specifies that the received data message should not be encrypted (e.g., specifies a default key identifier that corresponds to a no-encryption operation).

When the process 600 determines (at 630) that the data message should not be encrypted, the process sends (at 635) the message unencrypted along the message's datapath. This operation 630 entails informing its SFE port 260 that it has completed processing the data message. After 630, the process transitions to 635, where in the connection state cache storage 225, it creates a record to indicate that no encryption should be performed for the received data message flow. In some embodiments, this record is addressed in the connection state cache 225 based on the five-tuple identifier of this flow. After 635, the process ends.

When the process determines (at 630) that the data message should be encrypted, the process then (at 640) retrieves a key identifier from the identified rule, uses this identifier to retrieve a key from a local or remote key data store, as described above, and encrypts the received data message with the retrieved key. This encryption of the data message (at 635) is identical to the encryption operation 615 that was above described. For instance, as described above, the process 600 encrypts the data message's payload (e.g., the L2 payload) by using the identified encryption key, while performing ICV operation on the payload and some or all of the header values (e.g., the physical L3 and L4 header values, logical L2 or L3 header values, and/or the logical network identifiers, such as VNIs and VDRIs). For some or all of the data messages, the encryption process 600 in some embodiments also encrypts (at 640) some or all of the data message's header.

After encrypting the data message, the process sends (at 635) the encrypted data message along its datapath. Again, in some embodiments, this operation entails returning a communication to the SFE port 260 to let the port know that the encryptor is done with its processing of the data message. The SFE port 260 can then handoff the data message to the SFE 210 or can call another I/O chain operator to perform another operation on the data message.

When the encryption rule that is identified at 630 is a rule that was dynamically created after dynamically detecting an event, the encryptor has to make sure (at 640) that the key identifier for the key that is used to encrypt the data message is included in the data message header before it is sent. The process 600 accomplishes this goal differently in different embodiments. In some embodiments, the process 600 passes (at 640) the key identifier to the SFE port 260 (that called it) so that the port or an I/O chain operator that it calls can insert the key identifier in the data message header. For instance, in some embodiments, one service engine (e.g., another I/O chain operator) encapsulates the data message with a tunnel header that is used to establish an overlay logical network. In some of these embodiments, the SFE port 260 passes the key identifier that it receives from the process 600 to this service engine so that it can include this key identifier in its header.

In other embodiments, the process 600 does not pass a key identifier to the SFE port and this port does not have another service engine encapsulate a key identifier in the overlay network's tunnel header. In some of these embodiments, the SFE port 260 simply has the service engine include in the overlay network's tunnel header an indication that the data message is encrypted. In these embodiments, a decryptor (e.g., an encryption engine 124) executing on the host with the destination DCN can identify the correct key to use to decrypt the data message based on preconfigured information (e.g., a whitebox solution that allows the decryptor to pick the correct key based on a prior key specified for communicating with the source DCN, or based on header values of the data message flow), or based on out-of-band communication with a controller or a module on the source host regarding the appropriate key to use.

After 640, the process transitions to 645, where in the connection state cache storage 225, it creates a record to store either the encryption rule identified at 625, a reference to this encryption rule, the key identifier specified in this encryption rule, or the retrieved key specified by this key identifier. As mentioned above, this cached record has a record identifier that in some embodiments includes the received data message's identifier (e.g., five-tuple identifier). After 645, the process ends.

FIG. 7 illustrates a process 700 that an encryption engine 124 performs to decrypt an encrypted data message that an SFE port 260 or 265 receives on a destination host that executes the destination VM of the data message. This encryption engine is referred to as the decryptor below. In some embodiments, the decryptor performs this operation when its corresponding SFE port calls the decryptor to check whether a received data message is encrypted, and if so, to decrypt this message.

In some embodiments, the SFE port calls the encryption engine 124 when the SFE port determines that the received data message is encrypted. For instance, in some embodiments, the data message is sent to the destination host along a tunnel, and the header for this tunnel has an identifier that specifies that the data message is encrypted. In some embodiments, the decryptor performs this process only if the header value of the received data message does not specify a key identifier that identifies a key for decrypting the data message. When the header value does specify such a key identifier, the decryptor uses a decryption process 800 of FIG. 8, which will be described below.

Also, in some embodiments, the received data message has a value (e.g., a bit) that specifies whether the message is encrypted. By analyzing this value, the decryptor will know whether the message is encrypted. When this value specifies that the message is not encrypted, the decryptor does not call either the process 700 or 800 to decrypt the encrypted message. Instead, the decryptor informs the SFE port that it can send the data message along its datapath.

As shown, the process 700 initially identifies (at 705) a set of message attributes that the process uses to identify an encryption rule that is applicable to the received data message. In different embodiments, the message-attribute set that is used to retrieve the rule can be different. For example, in some embodiments, this message-attribute set includes the received data message's five-tuple identifier. In some embodiments, this message-attribute set also includes the logical network identifier associated with the received data message.

After 705, the decryptor determines (at 710) whether its encryption state cache 410 stores a cached encryption rule for the message attribute set identified at 705. Like an encryptor, each time a decryptor finds an encryption rule for a data message in some embodiments, it stores the encryption rule, a reference to the encryption rule, this rule's key identifier or this rule's key in the connection state cache 225, so that when it receives another data message with the same identified message-attribute set (e.g., when it received another data message that is part of the same data flow as the original data message), the decryptor does not have to search the encryption rule data store(s) to identify an encryption rule for the subsequently received data message. As mentioned above, the connection state cache 225, in some embodiments, stores the encryption rules based on five-tuple identifiers of the data messages. Accordingly, before searching the encryption rule data store 140, the decryptor in some embodiments first determines whether the connection state cache 225 stores a matching cached record for the received data message.

When the process 700 identifies (at 710) matching cached record for the received data message in the connection state cache 225, the process (at 715) then uses this record to identify a key, which it then uses to decrypts the encrypted portion of the received data message. In some embodiments, the cached record includes the key, while in other embodiments, this record includes the key identifier or the rule or a reference to the rule, which contains the key identifier. In the latter embodiments, the process uses the key identifier in the cached record or in the stored or referenced rule to retrieve a key from a local or remote key data store, and then decrypts the encrypted portion of the received data message with the retrieved key.

In some embodiments, part of the decryption operation (at 715) is to authenticate the ICV generated hash of the data message header and payload. Specifically, when a portion of the received data message (e.g., its physical (e.g., L3 or L4) header values, or its logical (e.g., VNI) header values) is hashed along with the payload through an ICV operation by the encryptor, the decryption operation verifies this portion to validate the authenticity and integrity of the encrypted data message.

After decrypting the data message (at 715), the process (at 715) sends the decrypted data message along its datapath. In some embodiments, this operation entails returning a communication to the SFE port (that called the decryptor to initiate the process 700) to let the port know that the decryptor is done with its processing of the data message. The SFE port can then allow the data message to reach the destination VM or can call another I/O chain operator to perform another operation on the data message. After 715, the process 700 ends.

When the process 700 determines (at 710) that the connection state cache 225 does not store an encryption rule for the attribute set identified at 705, the process 700 searches (at 720) the encryption rule data store 140 to identify an encryption rule for the received data message. In some embodiments, the destination host receives an out-of-band communication from the source host (directly or through a controller set) that provides data from which the destination host can identify a key identifier, or an encryption rule with the key identifier, for decrypting the encrypted data message. In some of these embodiments, the out-of-band communication includes the identifier (e.g., five-tuple identifier) for the data message.

In other embodiments, the encryption engine 124 on the destination host identifies the correct key to use to decrypt the data message based on preconfigured information. For example, in some embodiments, the encryption engines 124 on source and destination hosts use a whitebox solution (1) that steps through encryption keys according to a preconfigured scheme, or (2) that selects encryption keys based on attributes (e.g., five-tuple identifiers) of the data messages. By having the source and destination encryption engines follow the same scheme to step through or select the encryption keys, the whitebox scheme ensures that the encryption engine at the destination host's encryptor 124 can select the same encryption key for decrypting the received data message as the source host's encryptor 124 used to encrypt the data message.

When the process 700 cannot find an encryption rule that identifies a key, the process 700 in some embodiments initiates an error handling process to resolve the unavailability of a decryption key for decrypting the encrypted message. This error handling process in some embodiments queries a network agent to determine whether it or the controller set stores an encryption rule for the message attribute set identified at 705. When the agent has such an encryption rule, it provides it to the process (at 720). However, in other embodiments, the error handling process does not contact the network agent to obtain the key. Instead, it just flags this issue for an administrator to resolve.

When that the process identifies (at 720) a key identifier or an encryption rule with a key identifier, the process (at 725) uses the key identifier to retrieve a key from a local or remote key data store, and decrypts the received data message with the retrieved key. In some embodiments, part of the decryption operation (at 725) is to authenticate an ICV generated hash of the data message header and payload. Specifically, when a portion of the received data message (e.g., its physical (e.g., L3 or L4) header values, or its logical (e.g., VNI) header values) is hashed through an ICV operation along with the payload by the encryptor, the decryption operation verifies this portion to validate the authenticity and integrity of the encrypted data message.

After decrypting the data message, the process (at 725) sends the decrypted data message along its datapath. In some embodiments, this operation entails returning a communication to the SFE port (that called the decryptor to initiate the process 700) to let the port know that the decryptor is done with its processing of the data message. The SFE port can then allow the data message to reach the destination VM or can call another I/O chain operator to perform another operation on the data message.

After 725, the process transitions to 730, where in the connection state cache storage 225, it creates a record to specify that decryption key, or the identifier to this key, that should be used to decrypt data messages with message-attribute sets that are similar to the set identified at 705. In some embodiments, this record is addressed in the connection state cache 225 based on the five-tuple identifier of the received data message. After 730, the process ends.

In some embodiments, the header value (e.g., the tunnel header) of the received encrypted data message stores a key identifier that identifies a key for decrypting the data message. The encryption engine 124 on a host device then performs its decryption operation by using the key identified by the key identifier. FIG. 8 illustrates a process 800 that the encryption engine 124 performs to decrypt an encrypted data message that includes the key identifier in its header. In some embodiments, a decryptor in the encryption engine 124 performs this operation when its corresponding SFE port 260 or 265 calls the decryptor to check whether a received data message is encrypted, and if so, to decrypt this message. In some embodiments, the decryptor performs this process only if the header value of the received data message specifies a key identifier that identifies a key for decrypting the data message.

As shown, the process 800 initially extracts (at 805) the key identifier from the received data message. Next, the process uses (at 810) the key identifier to retrieve a key from a local key data store on the destination host or a remote key data store not on the destination host, and then uses (at 815) this key to decrypt the received data message. As mentioned above, part of the decryption (at 815) is to authenticate the ICV generated hash (of the received data message's header and payload) that is encrypted with the payload of the data message.

After decrypting the data message, the process sends (at 820) the decrypted data message along its datapath. In some embodiments, this operation entails returning a communication to the SFE port (that called the decryptor to initiate the process 800) to let the port know that the decryptor is done with its processing of the data message. The SFE port can then allow the data message to reach the destination VM or can call another I/O chain operator to perform another operation on the data message. After 820, the process 800 ends.

Because of its use of contextual attributes to define the rule identifiers of the Encryption rules, the context-based encryptor 124 can distribute the data message flows based on any number of contextual attributes. As mentioned above, examples of such encryption operations include: (1) encrypt all traffic from Outlook (started on any machine) to Exchange Server, (2) encrypt all communication between applications in a three tier Webserver, Application Server and Database Server, (3) encrypt all traffic originating from the Administrators Active Directory group, etc.

In some embodiments, the management plane obtains an inventory of all processes and services that are running on the VMs on the hosts in a datacenter. The discovery engine 120 of a host 200 in some embodiments assists in collecting this data from the VMs executing on its host. In some embodiments, the inventoried process/services are referred to as the inventoried applications, which include all client processes, services or daemons that utilize network input/output and all server processes that have registered to listen to (i.e., to obtain messages) certain network connections. The discovery engine collects this data using the GI agents 250 and the MUX 227 in some embodiments.

Based on the data collected by all the discovery engines on all the hosts, the management servers (e.g., the network managers and/or compute managers) build the inventory of the running applications. In some embodiments, each application is identified by comparing its file hash obtained from the VMs 205 with hashes of application files stored in the application data storage of the management plane. The management plane in some embodiments has the discovery engines update their data collection so that the management plane can refresh its inventory on a scheduled basis.

The management plane in some embodiments then provides a rule creation interface for allowing administrators to create context-based encryption rules and/or policies for the encryption engines 124 (as well as service rules for the other service engines 130). The rule creation interface allows the administrators to define high-level encryption policies (and other service policies) based on applications inventoried through the data collected by the discovery engines 120, and contextual attributes collected by the context engines 110 and by the management plane's interface with other management server clusters.

Once the high-level encryption policies (and other service policies) are defined in the management plane, the management plane directly supplies some or all of these policies to the management proxies (not shown) on the hosts 200, and/or indirectly supplies some or all of these policies to these proxies through a set of controllers (e.g., network controllers). In some embodiments, the management proxies publish the received policies as rules to the context-based service rule storages 140. In some embodiments, the proxies transform these policies before publishing them to the context-based service rule storages 140. For instance, in some embodiments, the policies are published with AppliedTo tuples that identify the service nodes and/or logical networks to which they are associated. In some of these embodiments, the management proxies on the hosts remove the AppliedTo tuple from each service policy, before pushing the policy as a service rule to the service engine 130. Also, as mentioned above, the context engines 110 on the hosts 200 in some embodiments resolve the policies based on collected contextual attributes, in order to generate rules for the service engines.

FIG. 9 illustrates an example of how the service engines 130 are managed in some embodiments. This figure illustrates multiple hosts 200 in a datacenter. As shown, each host includes several service engines 115, a context engine 110, a threat detector 132, a DPI module 135, several VMs 205, and an SFE 210. It also illustrates a set of controllers 910 for managing the service engines 115, VMs 205, and SFEs 210. As mentioned above, the context engines 110 in some embodiments collect contextual attributes that are passed to the management servers in the controller set through a network 950 (e.g., through a local area network, a wide area network, a network of networks (such as the Internet), etc.). The controller set provides a user interface for the administrators to define context-based service rules in terms of these collected contextual attributes, and communicates with the hosts through the network 950 to provide these policies. The hosts also communicatively connect to each other through this network 950.

Many of the above-described features and applications are implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, CD-ROMs, flash drives, RAM chips, hard drives, EPROMs, etc. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections.

In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage, which can be read into memory for processing by a processor. Also, in some embodiments, multiple software inventions can be implemented as sub-parts of a larger program while remaining distinct software inventions. In some embodiments, multiple software inventions can also be implemented as separate programs. Finally, any combination of separate programs that together implement a software invention described here is within the scope of the invention. In some embodiments, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs.

FIG. 10 conceptually illustrates a computer system 1000 with which some embodiments of the invention are implemented. The computer system 1000 can be used to implement any of the above-described hosts, controllers, and managers. As such, it can be used to execute any of the above described processes. This computer system includes various types of non-transitory machine readable media and interfaces for various other types of machine readable media. Computer system 1000 includes a bus 1005, processing unit(s) 1010, a system memory 1025, a read-only memory 1030, a permanent storage device 1035, input devices 1040, and output devices 1045.

The bus 1005 collectively represents all system, peripheral, and chipset buses that communicatively connect the numerous internal devices of the computer system 1000. For instance, the bus 1005 communicatively connects the processing unit(s) 1010 with the read-only memory 1030, the system memory 1025, and the permanent storage device 1035.

From these various memory units, the processing unit(s) 1010 retrieve instructions to execute and data to process in order to execute the processes of the invention. The processing unit(s) may be a single processor or a multi-core processor in different embodiments. The read-only-memory (ROM) 1030 stores static data and instructions that are needed by the processing unit(s) 1010 and other modules of the computer system. The permanent storage device 1035, on the other hand, is a read-and-write memory device. This device is a non-volatile memory unit that stores instructions and data even when the computer system 1000 is off. Some embodiments of the invention use a mass-storage device (such as a magnetic or optical disk and its corresponding disk drive) as the permanent storage device 1035.

Other embodiments use a removable storage device (such as a floppy disk, flash drive, etc.) as the permanent storage device Like the permanent storage device 1035, the system memory 1025 is a read-and-write memory device. However, unlike storage device 1035, the system memory is a volatile read-and-write memory, such a random access memory. The system memory stores some of the instructions and data that the processor needs at runtime. In some embodiments, the invention's processes are stored in the system memory 1025, the permanent storage device 1035, and/or the read-only memory 1030. From these various memory units, the processing unit(s) 1010 retrieve instructions to execute and data to process in order to execute the processes of some embodiments.

The bus 1005 also connects to the input and output devices 1040 and 1045. The input devices enable the user to communicate information and select commands to the computer system. The input devices 1040 include alphanumeric keyboards and pointing devices (also called “cursor control devices”). The output devices 1045 display images generated by the computer system. The output devices include printers and display devices, such as cathode ray tubes (CRT) or liquid crystal displays (LCD). Some embodiments include devices such as a touchscreen that function as both input and output devices.

Finally, as shown in FIG. 10, bus 1005 also couples computer system 1000 to a network 1065 through a network adapter (not shown). In this manner, the computer can be a part of a network of computers (such as a local area network (“LAN”), a wide area network (“WAN”), or an Intranet, or a network of networks, such as the Internet. Any or all components of computer system 1000 may be used in conjunction with the invention.

Some embodiments include electronic components, such as microprocessors, storage and memory that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic and/or solid state hard drives, read-only and recordable Blu-Ray® discs, ultra-density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media may store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter.

While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some embodiments are performed by one or more integrated circuits, such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some embodiments, such integrated circuits execute instructions that are stored on the circuit itself.

As used in this specification, the terms “computer”, “server”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms display or displaying means displaying on an electronic device. As used in this specification, the terms “computer readable medium,” “computer readable media,” and “machine readable medium” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral or transitory signals.

While the invention has been described with reference to numerous specific details, one of ordinary skill in the art will recognize that the invention can be embodied in other specific forms without departing from the spirit of the invention. For instance, several figures conceptually illustrate processes. The specific operations of these processes may not be performed in the exact order shown and described. The specific operations may not be performed in one continuous series of operations, and different specific operations may be performed in different embodiments. Furthermore, the process could be implemented using several sub-processes, or as part of a larger macro process. Thus, one of ordinary skill in the art would understand that the invention is not to be limited by the foregoing illustrative details, but rather is to be defined by the appended claims 

What is claimed is:
 1. A method of encrypting data messages sent by a first machine executing on a first host computer with a plurality of other machines, the method comprising: at an encryption module executing on the first host computer independently of the first machine, receiving a data message sent by the first machine addressed to a second machine executing on a second host computer; identifying a set of attributes associated with the first machine, the set of attributes including attributes other than layer 2 (L2), layer 3 (L3), and layer 4 (L4) data-message header values; using the identified set of attributes to identify an encryption rule; encrypting the data message based on the encryption rule; and sending, separately from the data message, an out-of-band message to the second host computer, the out-of-band message comprising an identifier for identifying the data message and a key identifier for identifying a key for decrypting the encrypted data message.
 2. The method of claim 1, wherein the identified set of attributes includes an application identifier that identifies a traffic type for a payload data contained within a data message flow of the data message.
 3. The method of claim 1, wherein the identified set of attributes includes an identifier of a user logged on to the first machine.
 4. The method of claim 3, wherein the user identifier is a group identifier.
 5. The method of claim 3, wherein the user identifier is an identifier that identifies a single individual.
 6. The method of claim 1, wherein the identified set of attributes includes a threat level associated with an application that executes on the first machine.
 7. The method of claim 6, wherein the application is an application that sent the data message.
 8. The method of claim 6, wherein the application is not an application that sent the data message.
 9. A non-transitory machine readable medium storing a program for encrypting data messages sent by a first machine executing on a first host computer with a plurality of other machines, the program comprising sets of instructions for: receiving a data message sent by the first machine addressed to a second machine executing on a second host computer; identifying a set of attributes associated with the first machine, the set of attributes including attributes other than layer 2 (L2), layer 3 (L3), and layer 4 (L4) data-message header values; using the identified set of attributes to identify an encryption rule; encrypting the data message based on the encryption rule; and sending, separately from the data message, an out-of-band message to the second host computer, the out-of-band message comprising an identifier for identifying the data message and a key identifier for identifying a key for decrypting the encrypted data message.
 10. The non-transitory machine readable medium of claim 9, wherein the set of instructions for identifying the set of attributes comprises a set of instructions for providing an identifier contained within the data message to a context-resolving engine to obtain at least a subset of the attributes that includes non-L2-L4 header values.
 11. The non-transitory machine readable medium of claim 10, wherein the identifier provided to the context-resolving engine comprises source IP (Internet Protocol) address, destination IP address, source port, destination port, and protocol header values of the data message.
 12. The non-transitory machine readable medium of claim 10, wherein the identifier provided to the context-resolving engine comprises a service tag embedded in the header values of the data message.
 13. The non-transitory machine readable medium of claim 9, wherein the first machine is a virtual machine (VM).
 14. The non-transitory machine readable medium of claim 9, wherein the first machine is a container.
 15. The non-transitory machine readable medium of claim 9, wherein the encryption rule comprises the key identifier that is used to identify the key for encrypting the data message.
 16. The non-transitory machine readable medium of claim 9, wherein the identified set of attributes includes an identifier of a user logged on to the first machine.
 17. The non-transitory machine readable medium of claim 16, wherein the user identifier is a group identifier. 